Inside pipe cutter



June 2, 1953 c. R. EDWARDS 5. 9

INSIDE PIPE CUTTER Original Filed May 15, 1940 CHARLES R- EDWARDS, PECEASER BY FRANCES R. EDWARDS, EXECTRIX MWJMM Patented June 2, 1953 'UNITED STATES TENT OFFICE INSIDE PIPE CUTTER Charles R. Edwards, deceased, late of Houston, Tex, by Frances Robertha Edwards, executrix,

Houston, Tex.

4 Claims.

This invention relates to new and useful improvements in means for recovering elements from well bores.

In the well art, it is well known that in the drilling and completion of wells, pipe, in one form or another, is substantially at all times extending into the well bore. During the actual drilling, the drill stem or pipe, which is made up of sections connected by coupling collars, has the drill bit mounted on its lower end and is rotatable so as to rotate the bit and perform the drilling operation. After the well is drilled in, well tubing and easing are disposed within the well bore and, of course, remain therein so long as the well is producing. The tubing extending into the well bore may separate, collapse or for other reasons, may fall downwardly in the bore to the bottom thereof; or the wall of the bore may cave in and firmly lodge the tubing, or a portion thereof, within the bore. When any of the foregoing occurs, it is necessary that the tubing be removed or fished out from the bore before the well operations may continue and manifestly, such removal, particularly where the tubing is firmly lodged or stuck within the bore, creates quite a which may have become lodged, or which may r have fallen downwardly, within a well bore.

A further object of the invention is to provide an improved means, which means is operable after effecting a removal of the unlodged or free portion of the pipe, and involves cutting the lodged portion of the pipe into sections by means of an inside cutter, whereby said lodged portion may be removed from the bore.

Another object of the invention is to provide an improved cutter having a positively driven feeding means therefor operable to be released instantly, and means to drive the cutter faster toward the tubing at the beginning of the out rather than when the cutting load increases due to a wider out.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in which an example of the invention is shown, and wherein:

Fig. 1 is a vertical View, partly in section and partly in elevation, of an inside cutter having its knives in their retracted postions and constructed in accordance with the invention;

Fig. 2 is a view similar to Fig. 1, showing the knives in their cutting positions;

Fig. 3 is a horizontal CIOSS-SBC'GOHELI view taken on the line 33 of Fig. 1;

Fig. 4 is a horizontal cross-sectional view take on the line ll -l of. Fig. l, and

Fig. 5 is a horizontal cross-sectional view taken.

on the line 55 of Fig. 1.

In recovering stuck tubing from a well, it is often necessary to cut the tubing in sections, and this may be done with what is commonly known as a pipe cutter, which is shown in Figs. 1 to 5, inclusive. I

An inside, releasable, cut-and-pull cutter is provided, having a hollow tubular mandrel '23? which has its upper end 238 externally screwthreaded so as to receive an adapter 239, which has its upper portion 240 internally screw-threaded to receive the end or" an operating string of pipe. The lower portion 2M of the mandrel 23'! has its outer surface 242 enlarged. The bore 243 is also enlarged, thus providing a shoulder 24 3 within the bore and a shoulder 245 on the outer surface of said mandrel. A sleeve 246 has its upper end lying within and under the adapter 239, and has an inner shoulder 24'! resting on a plurality of thrust bearing rings 248 which rest on the shoulder 245. The lower portion of the sleeve 2% forms an apron or skirt 259, whose inner surface is provided with fine screw-threads 258. The underside of the adapter 239 is provided with a central opening 25!. which has its inner surface internally screw-threaded. A spring 252, rectangular in cross-section, is provided with its upper end bent upwardly so as to form a vertical hook that engages in a small hole drilled in the downwardly-facing shoulder to cause the spring to turn with the adapter 239. This spring is coiled right-handed so as to grip a slip seat formed on the upper end of sleeve 245 in order to form a friction clutch that is de-energizing when rotating the mandrel 23'! clockwise, but is self-energizing when the mandrel is rotated counterclockwise. The spring 252 isplaced within said opening, and. the packing 253 is placed below said spring. A packing nut 254 is,

screwed into the opening 25% and packs off around the sleeve 2%. Loosely surrounding the sleeve 256 is a spring-tensioned gripping means or slip 255. The surface 256 of the sleeve 24 3 is tapered outwardly and downwardly to a point above the shoulder 2M. Formed on the lower portion of the taper 256 area plurality of guides,

251, between which the gripping wickers 263 of the spring-gripping means 255 slide down and are forced outwardly and into engagement with the casing 258. It is pointed out that said gripping means is provided with vertically extending slots 259 in its upper portion and similar slots 266 in its lower portion. A plurality of spring rings 261 urge the upper gripping surface 283 outwardly, and the lower end of said wickers will rest upon the guides 251; but when said gripping means 255 is relatively rotated so that the slots 266 will allow the gripping means 255 to slide downwardly between the guides 251 onto the tapered portion 256, the inclined surface 256 will urge the wickers 263 of the gripping means 255 outwardly, thereby allowing the wickers 263 of the gripping means 255 to securely engage the casing 258.

A piston 265 works within the enlarged bore below the shoulder 244, and will abut said shoulder when it is in its upward position. Said piston is provided with a head 266 which slidably engages the side walls of said enlarged bore, and a hollow stem 261 depends from said head. It is pointed out that said stem 261 is provided with an axial bore 268, and has its lower end 239 cut upwardly and inwardly to form a tapering valve seat. It will be noticed that the piston stem 26'! is outwardly tapered, and that its lower outside diameter is reduced at 216. Surrounding the tapered reduced portion is a split bolt to form a plurality of retractable feeding means 21! which have their outer arcuate edges 212 threaded so as to releasably engage the threads 256 of the lower portion 249 of the sleeve 246 (Figs. 1, 2 and 3). It can be seen in the drawings, that there has been provided three sections of said split bolt for this feeding means, however, any desirable number could be used. The mandrel 241 is provided with a plurality of openings or windows 213 into which the feeding means 211 are movably inserted, said openings being vertically larger than the sectional feeding means 21 I, and said feeding means being free to move up and down in said openings. Near the inner edge of each of said feeding means, there is provided a recess 214. In each of said recesses, there may be inserted a pin 215, and the uper end of each of said pins is attached to a fiat ring 216. Confined between the ring 216 and the underside of the piston head 265 is a coil spring 211. This spring will exert a downward pressure on the ring 216 and also on the pins 215. The underside of the feeding means 21! are cut inwardly to form tapers 213, and the spring 211 will act on the pins 215 and will constantly tend to tilt said means inwardly so that the thread teeth 212 will disengage with the thread teeth 256. However, when pump pressure is applied, it will act upon the piston head 268 to keep the tapered portion 216 of the piston stem 261 in engagement with the inner sides of the feeding means and the spring 211 will be unable to tilt said feeding means so as to release the same. Below the windows or openings 213, the mandrel 231 is provided with a plurality of similar windows or openings 219. A cutter or knifecarrier sleeve 286 slidably surrounds the rod of the piston 265. The lower portion of the knife-carrier sleeve 286 is enlarged so as to form a shoulder 281 upon which the split bolt feeding means 21! rest. The outer surface of the sleeve 286 slidably engages the bore of the mandrel 231. The inner bore of the knife-carrier sleeve 286 is enlarged near its lower portion to form a shoulder 282. Said knife-carrier sleeve is cut out so as to 4 form knife pockets 283, and has pivoted in the upper end of each of said pockets a cutter blade 284. It is obvious that any number of cutters may be used.

The lowermost end of the mandrel 231 is internally screw-threaded, and receives a plug 265 which has a plurality of cleaning blades 236 out or. milled in its extreme lower end. The plug 285 is provided with an internally screw-threaded axial bore 281, and surrounding said bore is a plurality of elongated openings 238 through which water or the like may flow. Screwthreadedly attached to the bore 231 is a stop pin 289 which has a cone-shaped valve head 296 on its upper end so as to snugly fit the valve seat 269, and its shank 25 is externally screw-threaded. A lock bolt 292 is inserted below the lowermost end of the shank 29!, thereby locking said valve pin in position. A retaining ring 293 abuts the shoulder 282 of the sleeve 286 so as to force the knife or cutter blades in into the windows 219 and thus limit the upward travel of the cutter carrier 288. Confined beneath said retaining ring and resting upon the plug 285 is a coil spring 294, so as to lift the cutter carrier 286 and retract the cutter blades 284.

In operation, a tubing or pipe (not shown) is connected to the adapter 239 by means of the screw threads 248, and the cutter is lowered into the well bore. When said cutter is lowered into the well, it will be in the position shown in Fig. 1, having the knives 284 retracted and the feeding means 21l--212 near the upper end of the opening 213. The gripping means 255 will be resting upon the tapered portion 256 and the guides 251 so that the gripping means may not become engaged with the casing 253. In case any loose material has become lodged in the stuck tubing, the circulation can be started and the cutter rotated down in the stuck tubing so as to remove said material; the object being to permit free downward passage of the cutter.

When the point is reached at which cutting is desired, the gripping means 255 is moved off the tapered portions of the guides by a slight rotation and allowed to move down onto the tapered surface 256. As the pipe (not shown) is pulled up, the device will also move upwardly, and the gripping means, due to the frictional engagement, will be pulled downwardly over the tapered portion 256, thereby securely holding said device firmly within the stuck tubing in the well bore. Then, the pipe is rotated, which will rotate the head 239 and the mandrel 231. The sleeve 246 does not rotate because the guides 251 will lie in the slots 266 of the engaged slip 263' and the gripping means will be firmly held against rotation; thus the screw-threaded end 256 will also be held against rotation. As the mandrel 231 is rotated, the feeding means 21!, having been engaged with threads 256 by fluid pressure, will travel downwardly by medium of the threads 212 on the feeding means 21!. The threads 256 on the lower end of the skirt 249 of the sleeve 2 26 will also carry the piston 255 downwardly, as will the member 286, which will push the knives 284 outwardly through the openings 219 of the mandrel 231 as the cutter mandrel is rotated; thus cutting the pipe. By this means, it is always possible to have a tension upon the cutting member and an eflicient rest for the mandrel.

Further, the cutting operation may be stopped at any time desired, and by relieving the fluid pressure, the two coil springs will retract the I cutters, By releasing the pump pressure from the head 266, the feeding means 2' will be tilted, due to the tapered lower surface 278, which will disengage the teeth 272 and 259, and will allow the spring 294 to move the structure upwardly. As can be seen in Fig. 2, after the knife has completely cut the pipe, the lower angular face 269 of the piston 265 will engage the cone-shaped valve top 290 of the pin 289. Thus, when said piston is firmly seated upon said cone, pump pressure will no longer be capable of flowing through said structure, and the operator is thus advised that he has a completed cut. The pin 239 is adjustable so that the piston 2'65 varies. The cutting operation may be stopped at any point, thereby reducing the possibility of breaking the knives or cutters, Often the knives or cutters will vibrate or skip, thus causing gouging of the casing or breaking of the knives. The slow and positive feeding means prevents such gouging or breakage done by the knives in the usual cutters and thereby results in a more eflicient inside cutter.

This application is a division of co-pending application, Serial No. 598,810, filed June 11, 1945, for Pipe Cutters, now Patent Number 2,572,997, issued October 30, 1951, which in turn is a division of Serial No. 334,947, filed May 13, 1940, for Methods and Means for Recovering Elements From Well Bores, now Patent No. 2,394,759, issued February 12, 1946.

Other modes of applying the principle of the invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

What is particularly pointed out and claimed as the invention is:

1. An inside pipe cutting tool comprising an inner mandrel, a sleeve surrounding a part of said mandrel, a pipe gripping means surrounding a part of said sleeve and pipe cutting means; said pipe cutting means being operable by fluid contained in said mandrel, and including a piston mounted in an enlarged bore of said mandrel.

2. An inside pipe cutting tool comprising an inner mandrel, a sleeve surrounding a part of said mandrel, a pipe gripping means surrounding a part of said sleeve and pipe cutting means; said pipe cutting means being operable by fluid contained in said mandrel, and including a piston mounted in an enlarged bore of said mandrel, and cutter knives actuated upon axial movement of said piston with respect to said mandrel.

3. An inside pipe cutting tool comprising an inner mandrel, a sleeve, surrounding a part of said mandrel, a pipe gripping means surrounding a part of said sleeve and pipe cutting means;

said pipe cutting means being operable by fluid contained in said mandrel, and including a piston mounted in an enlarged :bore of said mandrel, and cutter knives actuated upon axial movement of said piston with respect to said mandrel, said cutter knives being mounted in member surrounding a stem depending from said piston.

4. An inside pipe cutting tool comprising an inner mandrel, a sleeve surrounding a part of said mandrel, a pipe gripping means surrounding a part of said sleeve and pipe cutting means; said pipe cutting means being operable by fluid contained in said mandrel, and including a piston mounted in an enlarged bore of said mandrel, and cutter knives actuated upon axial movement of said piston with respect to said mandrel, said cutter knives being mounted in a member surrounding a stem depending from said piston, there being a split bolt mounted between the head of said piston and said member, said split bolt having circumferential portions th-readedly engaged with a portion of the bore of said sleeve.

FRANCES ROBERTHA EDWARDS, Executria: of the estate of Charles R. Edwards,

deceased.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,773,389 Church Aug. 19, 1930 1,927,310 Edwards Sept. 19, 1933 2,167,445 Brown July 25, 1939 2,215,638 Ellis Sept. 24, 1940 

